Method for applying road markers



United States Patent ington No Drawing. Filed Jan. 29, 1962, Ser. No.169,584 12 Claims. (Cl. 94-22) This invention relates to a newand'useful process for applying road markers tothe surfaces of roadwaysand more particularly to a method for applying buttons or markers to aroadway surface which results in a semipermanent installation of saidmarkers.

The present trend toward the marking of roadway surfaces withraisedbuttons has been precipitated by a number of factors. Paint lines mustbe reapplied approximately every six months. In wet weather paint lines.hecome practically invisible, due to the sheet of water which coversthe-roadway surface. This latter fact is particularly true at night.Raisedmarkers installed on the roadway surface are not obscured in wet,dark weather. While the process of this invention is primarily concernedwith markers over which traffic will pass nevertheless it may also beused for larger obstacle type channeling or markers.

The markers with which the process is concerned are exposed to shocksand impacts delivered by automobile, truck and other tires passingthereover. Such impact loading requires that the marker be adhered tothe roadway surface by an extremely high strength bond. Furthermore, itis axiomatic that the marker be installed in place in an absoluteminimum amount of time so that sections of the roadway itself are notout of use for any prolonged period.

The use of heat to install markers in the manner hereafter described haa further advantage in that markers can be installed with equal facilityduring very cold, or very hot weather, or even in rain or lightsnowfall. Heating both the road surface and the marker assuresuniformity of cure time and maximum cure of the adhesive. Thcrmosettingthe adhesivev usually produces a stronger bond on a variety of surfaces.Thus the process is useful for bonding marker to concrete, asphalt,steel bridge deck surfaces and the like.

The process of this invention utilizes a high strength, thermosettingsynthetic resin cured by means of heat which is applied to both thesurface of the roadway and the marker. The road surface and the markerare generally heated simultaneously. Thus, the thermosetting resin whichis unheated before its application to the roadway is cured or set byheat from both the pavement surface and from the marker.

According to the invention the markers are heated by immersing them in ahot fluid. The fluid may be air, as an oven, or a liquid. Liquidimmersion is preferred. The exact temperature may vary within a widerange, being limited on the high end only by temperatures which woulddamage the markers and on the low end by temperatures which incombination with an insufficiently heated road surface would notthermoset the adhesive.

Accordingly, it is an object of this invention to provide a process forinstalling traiiic markers on roadway surfaces which is economical incost and simple in its application.

Another object of this invention is to provide a process for installingmarkers which is fast and efficient.

Yet another object of this invention is a process for installing tratlicmarkers which results in a bond between ice marker and roadway surfacewhich is generally stronger than the material of which the roadwayisconstructed.

Still another object of this invention is a process which may be used inhot, cold or wet weather.

An additional object of the invention-is to provide a system to installmarkers on new roadway before it is opened to tra-fiic and which isequally applicable to installation on roadways which are in'use. In thislatter case it is particularly important that the adhesive have rapidsetting characteristics toreduce the time of tratiic interference to aminimum.

An even further object of this invention is aprocess which is so simplethat it allows installation crew to be trained rapidly and while on thejob.

Yet a further object of this invention is to provide a process giving abond which, after curing, is unaffected by wide variations intemperature or moisture conditions.

These, together with other objects and advantages which will becomesubsequently apparent, reside in the details of the process as morefully hereinafter described and claimed.

The markers may take any desired shape but must be substantially fiat onthe side which is to contact the roadwaysurface. The markers are,conventionally, round, flat on the bottomand convex on the upper side,thus forming roughly and for general comparison purposes, a sphericalsegment. Said marker will usually be made of a synthetic resin material,such as alkyd orpolyester type resin, thoughfor purposes of this processmay be any type of solid and strong compositions capable of answering tothe needs of a trafiic marker. Other compositions which are used areglass, precast concrete, steel, and the like. Such needs include impactstrength, reflective ability,.wear properties and others.

The adhesive for bonding the markers to a roadway surface must provideprimarily a high strength bond between the'marker and roadway surface.Such adhesive may be any one of a number of well-known, highastrengthmaterials. Polyepoxides, commonly referred'to as epoxy resins, have beenshown to give excellent results in providing lasting, high strengthbonds. Such epoxy resin adhesives are usually the reaction products ofbisphenol-A and epichlorohydrin and are provided in small containers towhich is added a suitable catalyst just prior to the application to theroad surface. Since the adhesive is a thermosetting material no heat isrequired prior to its actual application to the roadway surface.

In order to prepare the pavement for placing the markers, it is onlynecessary to brush away gravel, sand, other loose material or standingwater prior to heating. When the pavement surface is free of loosematerial it is spot heated by radiant heat from a gas burner. Obviously,the spots or areas to be heated will be predetermined and will have beendesignated by chalk or paint or other means. In actual practice, anumber of spots on the pavement will be heated simultaneously. It hasbeen found that these markers may be installed over a wide. range ofambient temperatures. Obviously, the colder the ambient temperature thelonger the equipment will be required to heat the designated pavementspots. For instance, at temperatures of about 35 F. the pavement will beheated for about 30 seconds and for perhaps as much as a minute, or evenseconds. At the upper end of the temperature scale the pavement may needheating for as little as 5 to 10 seconds. The road surface ternperatureand the marker temperature should be at least high enough to provide aminimum temperature of F. within the adhesive film after the marker ispressed in place. A rapid setting type of epoxy adhesive has beenobserved to develop enough strength to permit reopening Q? the road totraffic in five minutes under this condition. It is to be further notedthat the pavement surface can be moist and even covered with a lightfilmv of water without hindering installation of this system.Inst-allation of markers according to this process, however, should notbe attempted in standing water.

The markers are usually heated during the time the pavement is beingprepared, i.e., cleaned, chalked and heated. The markers are taken froma container and usually a number of them are placed in small holders.The holders are then placed in a heated oven or immersed in a tank ofheating liquid maintained at about 275 F. and allowed to remain thereinuntil the markers themselves have been heated to approximately the sametemperature. Time required to raise the markers to the desired degree ofheat is a minimum of about ten minutes. As heated markers are removedfrom the holders cold ones are substituted to maintain a continuoussupply.

It should be mentioned that several disadvantages inhere in air heatingthe markers. Theheat capacity of the air is low and transfer of heatfrom the air tothe marker is slow. Furthermore, there is considerablevariation in the temperature of the air in the oven and heated air islost each time the oven is opened. Thus, maintaining the oventemperature becomes a problem. However, air can be and has been used inthis process.

When liquid immersion heating is employed for heating the markers theliquid must be compatible with the bonding adhesive, should not discolorthe marker and must not adversely react with the marker. A liquid whichcaused any appreciable dissolution of the marker surface would beunuseable.

Obviously such marker heating liquid must possess a high boiling point.polyether polyglycols and various mixtures thereof give excellentresults. Other polyglycols such as glycerol, ethylene glycol, diethyleneglycol are also suitable. Dow Chemical Companys polyglycol E300 isparticularly eflicient in the process and is preferred. As those skilledin the art will recognize other high boiling point liquids answering tothe specific requirements of this process are not excluded.

When the markers are brought up to temperature and immediately after theequipment has heated the pavement spots a quantity of adhesive is placedon the pavement spot to which the marker is to be attached. As soon asthe adhesive is down, a marker is placed on the bonding material andpressed down and rotated or twisted. In this way,.an even distributionof the adhesive is effected between the pavement surface and the flatmarker bottom. A certain amount of squeeze-out of the adhesive willresult from this manner of installation. Heat from both the marker andthe pavement accelerates the hardening or curing of the adhesive. Incold weather a bond willciently strong to resist traflic passing overthe freshly placed marker will result in about ten minutes. In warmweather the bond may cure or set in as little as 2 minutes. It will beapparent that this rapid cure of the adhesive means that the crew needonly tie up the pavement area for about 5 to minutes. Thus, a distinctadvantage is gained over paint striping and over slower setting markersystems. Hence, it will be seen that the employment of heat to bothmarker and pavement results in a rapid process for making a traflicmarking system. The installed markers form a semi-permanent installationin that the traffic lanes and other lines will endure for 5 to years.

It is felt that this process, together with the design of portable,semi-automatic equipment to serve this process is a great step forwardin the road marking art.

The foregoing is considered as illustrative only of the principle ofthis invention. Since numerous modifications and changes will readilyoccur to those skilled in the art, it is not desired to limit theinvention to the pre- To this end, it has been found that cise processshown and described, and accordingly all suitable modifications andequivalents may be resorted to, falling within the scope of theinvention.

What is claimed is:

1. A process for applying traflic markers to roadway surfaces,comprising: (a) cleaning and marking predetermined spots on the roadwaypavement, (b) simultaneously heating the markers to be applied to saidroadway surface in a high boiling point polyglycol liquid maintained ata temperature of 275 F., until said markers are approximately thetemperature of said liquid and heating said predetermined pavementspots, (c) applying an adhesive to said heated pavement spots forbonding said markers to said spots, (d) applying markers to saidadhesives, and (e) allowing said adhesive to harden to complete thebonding of said markers to said spots.

2. A process for applying trailic markers to roadway surfaces,comprising: (a) cleaning and marking predetermined spots on the roadwaypavement which are to receive the markers, (b) heating the markers to beapplied to said roadway surface in a high boiling .polyglycol liquidmaintained at a temperature of about 275 F., until said markers areapproximately the temperature of said liquid, (c) heating said spots,(d) applying an adhesive to said pavement spots for bonding said markersto said spots, (e) applying markers to said adhesive, and (f) allowingsaid adhesive to harden to complete the bonding of said markers to saidspots.

3. A process for applying traffic markers to roadway surfaces,comprising: (a) cleaning and marking a predetermined spot on the roadwaypavement which is to receive the marker, (b) heating the marker to beapplied to said spot to a temperature of about 275 F. in a highboilingpolyglycol liquid, (c) heating said spot, (d) apply ing adhesiveto said spot for bonding said marker to said spot, (e) pressing saidmarker onto said adhesive, and (f) allowing said adhesive to harden tocomplete the bonding of said marker to said spot.

4. A process for applying trafiic markers to roadway surfaces,comprising: (a) cleaning and marking a predetermined spot on the roadwaypavement which is to receive the marker, (b) heating the marker to beapplied to said spot in a high boiling polyglycol fluid maintained at atemperature of about 275 F. until said marker is approximately thetemperature of said fluid, (c) heating said spot with a radiant heater,(d) applying adhesive to said spot for bonding said marker to said spot,(e) pressing the marker onto said adhesive, and (f) allowing saidadhesive to harden to complete the bonding of said marker to said spot.

5. A process for applying traffic markers to roadway surfaces,comprising: (a) cleaning and marking a predetermined spot on the roadwaypavement which is to receive the marker, (b) heating the marker to. beapplied to said spot in a high boiling polyglycol fluid maintained at atemperature of about 275 F. until said marker is approximately thetemperature of said fluid, (c) heating said spot with'a radiant heater,(d) applying a thermosetting resin adhesive to said spot for bondingsaid marker to said spot, (e) pressing the marker onto said adhesive,and (f) allowing said adhesive to cure and harden to com plete thebonding of said marker to said spot.

6. A process for applying traflic markers to roadway surfaces,comprising: (a) cleaning and marking a predetermined spot on the roadwaypavement, (b) simultaneously heating the marker to be applied to saidroadway surface in a high boiling polyether polyglycol maintained at atemperature of about 275, F., until said marker is approximately thetemperature of said polyglycol and at the same time heating saidpredetermined pavement spot, (c) applying an adhesive to said heatedpavement spot for bonding said marker, to said spot, (d) applying aheated marker to said adhesive, and (e) allowing said adhesive to hardento complete the bonding of said marker to said spot.

7. A process for applying traffic markers to roadway surfaces,comprising: (a) cleaning and marking a predetermined spot on the roadwaypavement, (b) simultaneously heating the marker to be applied to saidroadway surface in a high boiling polyglycol liquid maintained at atemperature of about 275 F. until said marker is approximately thetemperature of said liquid, and at the same time heating saidpredetermined pavement spot, (c) applying an adhesive to said heatedpavement spot for bonding said marker to said spot, ((1) applying aheated marker to said adhesive, and (e) allowing said adhesive to hardento complete the bonding of said marker to said spot.

8. A process for applying traffic markers to roadway surfaces,comprising: (a) cleaning and marking a predetermined spot on the roadwaypavement, (b) simultaneously heating the marker to be applied to saidroadway surface in a high boiling polyether polyglycol liquid maintainedat a temperature of about 275 F. until said marker is approximately thetemperature of said liquid, and at the same time heating saidpredetermined pavement spot, (c) applying an adhesive to said heatedpavement spot for bonding said marker to said spot, (d) applying aheated marker to said adhesive, and (e) allowing said adhesive to hardento complete the bonding of said marker to said spot.

9. A process for applying traffic markers to roadway surfaces,comprising: (a) cleaning and marking a predetermined spot on the roadwaypavement, (b) simultaneously heating the marker to be applied to saidroadway surface in a high boiling polyglycol liquid maintained at atemperature of about 275 F. until said marker is approximately thetemperature of said liquid, and at the same time heating saidpredetermined pavement spot, (0) applying a thermosetting resin adhesiveto said spot for bonding said marker to said spot, (d) applying a heatedmarker to said adhesive so that the temperature of the adhesive betweensaid marker and said spot achieves at least about 180 F., and (e)allowing said adhesive to cure and harden to complete the bonding ofsaid marker to said spot.

10. A process for applying traflic markers to roadway surfaces,comprising: (a) cleaning and marking a predetermined spot on the roadwaypavement, (b) simultaneously heating the marker to be applied to saidroadway surface in a high boiling polyglycol liquid maintained at atemperature of about 275 F. until said marker is approximately thetemperature of said liquid, and at the same time heating saidpredetermined pavement spot, (0) applying an adhesive to said heatedpavement spot for bonding said marker to said spot, (d) applying aheated marker to said adhesive so that the temperature of the adhesivebetween said marker and said spot achieves a minimum of about 180 F.,and (e) allowing said adhesive to harden to complete the bonding of saidmarker to said spot.

11. A process for applying traffic markers to roadway surfaces,comprising: (a) cleaning and marking a predetermined spot on the roadwaypavement, (b) simultaneously heating the marker to be applied to saidroadway surface in a high boiling polyether polyglycol liquid maintainedat a temperature of about 275 F., until said marker is approximately thetemperature of said liquid, and at the same time heating saidpredetermined spot, (0) applying a thermosetting resin adhesive to saidspot for bonding said marker to said spot, (d) applying a heated markerto said adhesive so that the temperature of said adhesive between saidmarker and said spot achieves a minimum of about 180 F., and (e)allowing said adhesive to cure and harden to complete the bonding ofsaid marker to said spot.

12. A process for applying trafiic markers to roadway surfaces,comprising (a) heating a supply of markers to be applied to the roadwaysurface in a high boiling poly glycol liquid maintained at a temperatureof about 275 F., until said markers are approximately the temperature ofsaid liquid,

(b) heating the application area of the roadway surface (0) applying athermosetting adhesive to said area (d) applying said heated markers tosaid adhesive (e) allowing said adhesive to cure and harden to completethe bonding of said markers to said area.

References Cited by the Examiner UNITED STATES PATENTS 2,187,879 1/1940Johnson 94l.5 2,192,290 3/1940 ONeal 156-71 2,470,963 5/1949 Weyl156-320 2,849,933 9/1958 Von Hofe 156-320 2,898,825 8/1959 Walker et al.94-22 2,933,989 4/1960 DAdrian 94-15 2,952,192 9/1960 Nagin 94-153,086,431 4/1963 Perry 94-15 3,096,694 7/1963 Lynn 94-15 OTHERREFERENCES Thiokol Chem. Corp, Thio-line Traffic Buttons, June 30, 1960,pp. 1-7.

California Highway and Public Works, Traffic Bar, by Rooney et al.,February 1956, pp. 1 and 2.

ALEXANDER WYMAN, Primary Examiner.

HAROLD ANSHER, Examiner.

12. A PROCESS FOR APPLYING TRAFFIC MARKERS TO ROADWAY SURFACES,COMPRISING (A) HEATING A SUPPLY OF MARKERS TO BE APPLIED TO THE ROADWAYSURFACE IN A HIGH BOILING POLYGLYCOL LIQUID MAINTAINED AT A TEMPERATUREOF ABOUT 275* F., UNTIL SAID MARKERS ARE APPROXIMATELY THE TEMPERATUREOF SAID LIQUID, (B) HEATING THE APPLICATION AREA OF THE ROADWAY SURFACE(C) APPLYING A THERMOSETTING ADHESIVE TO SAID AREA (D) APPLYING SAIDHEATED MARKERS TO SAID ADHESIVE (E) ALLOWING SAID ADHESIVE TO CURE ANDHARDEN TO COMPLETE THE BONDING OF SAID MARKERS TO SAID AREA.